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Rayleigh-corrected reflectance (Rrc(λ))

Posted: Sat Sep 20, 2025 4:18 am America/New_York
by johan_ma
I am working on monitoring floating macroalgae (Ulva prolifera) and would like to use Rayleigh-corrected reflectance (Rrc(λ)) instead of the fully corrected remote sensing reflectance Rrs(λ). As pointed out by Chuanmin Hu , aerosol or other atmospheric corrections can fail for pixels containing U. prolifera because their strong NIR/SWIR reflectance contaminates the aerosol correction bands.

My goal is to use l2gen in SeaDAS to:
Input Level-1B data.
Output Rrc(λ) (TOA reflectance after Rayleigh correction only)

So far, I have found or tried the following:
Parameter aer_opt = -99 is mentioned to turn off aerosol correction.

Questions:
Is there a specific combination of l2gen parameters that will directly produce Rrc(λ)?
If not, which intermediate product(s) should I request (e.g., rhos)
Has anyone processed floating algae (like U. prolifera) with SeaDAS in a similar way and could share their settings or experience?

Any guidance or example configurations would be greatly appreciated.

Thanks in advance for your help

Re: Rayleigh-corrected reflectance (Rrc(λ))

Posted: Mon Sep 22, 2025 10:28 am America/New_York
by jared
Hi there,

Products "rhos" in SeaDAS is equivalante to Rrc.

Minwei

Re: Rayleigh-corrected reflectance (Rrc(λ))

Posted: Mon Sep 22, 2025 3:07 pm America/New_York
by OB.DAAC - SeanBailey
To add to Minwei's response...

rhos also accounts for gaseous absorption (in addition to simple Rayleigh scattering). It does not require "atmospheric correction" (really, aerosol correction...we're bad at being clear about what the parameters do), so you can set atmocor=0 to speed up the processing (aer_opt would therefore be irrelevant)

Regards,
Sean